It's kind of funny if you think about it. The purpose of the hard switch as told by the FSM is in case the soft setting (adjusting it to .46 volts) malfunctions. So it doesn't really matter what voltage you set it to as long as you set it to right when the closed switch is engaged (which normally should be around .46 volts). I think Nissan engineers knew that the spot where electrical current is more constantly going through the resistor board would eventually break down so they put the hard switch in there as a backup. The type of resistor board in the TPS is the same type in things such as volume controls and not meant to handle very large amounts of current. There are potentiometers that do handle larger currents and can last forever. I don't understand why they didn't use a type like that other than it didn't matter because either way they wanted a fail safe backup. Another way to set the TPS position which may be better to compansate for not so good working TPS sensors would be to attach a multimeter set to check continuity to the closed throttle switch and adjust the TPS to right at the point where the switch closes.
